Improvement in screw-cutting dies



J..F C RIDER.

SCREW CUTTING DIES.

No.175,380. Patented March 28,1876

WITNESSES:

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N.PETERS, FHOTO-LITNDGRAPHER. WASHINGTON. D C.

UNITED STATES JOHN F. c. RIDER,

PATENT OFFICE.

OF SOUTH NEW MARKET, NEW HAMPSHIRE, ASSIGNOR TO HELEN A. RIDER, OF SAMEPLACE.

IMPROVEMENT IN SCREW-CUTTING DIES.

Specification forming part of Letters Patent No. 175,380, dated March28, 1876; application filed July 30, 1873.

To all whom it may concern:

Be it known that I, JOHN F. O. RIDER, of South New Market, county ofRockingham, State of New Hampshire, have invented an improved Die forScrew-Cutting Die-Plates, of which the following is a specification:

This invention relates to an vimproved construction of die for cuttingscrews on pipes, bolts, and rods, to be used in an ordinary plate orstock, the cutters being of steel in small pieces, and inserted in amalleable-iron body in which they are fastened by brazing, as I will nowdescribe in such a manner as to be removable.

In the drawings, Figure 1 is a plan, and Fig. 2 a section, of myimproved die.

A is the blank in which the small cutters a a a a are inserted, theinner ends of the same being properly formed for cutting the desiredthread.

I form the die with openings or slots therein to receive the cutters a,a a a, previously fitted for insertion, and braze the cutters tightlyinto the slots so formed in the blank.

- When so brazed the implement can be made at a greatly-reduced cost,and is a much better tool than as ordinarily made, and finer steel canbe used and in very small bars, and

they can be repaired and made equal to new at slight expense. Besides, Iavoid the loss of many tools consequent upon making the whole implementsolid, and the tool is much lighter.

By this method of constructing dies I am able to insert hardened andtempered steel dies in malleable-iron blanks or receivers without dangerof impairing their cutting qualities, making a die equally as good as asolid steel die and at a low cost.

The blank A may be formed of composition, and the cutters fastened in,as shown; but I prefer malleable iron on account of its cheapness, whileit is otherwise Well suited to the purpose, or the blank may be formedof other metal, if preferred.

I claim- .lhe within-described die as an article of manufacture,consisting of a stock and of steel bits or cutters securely and firmlyconnected therewith, and adapted. to be removed and adjusted,substantially as shown and described.

' JOHN F. O. RIDER.

Witnesses:

- J osEPH B. GARDINER, SAML. F. THoMPsoN.

